Enjoying EarthSky? Subscribe.

251,773 subscribers and counting ...

Full-sphere, 360-degree ISS transit

Super cool, interactive image of a transit across the sky of the International Space Station – from May 26, 2017 – by Project Nightflight of Austria.

Two big asteroids to pass safely

Radar astronomers are peering toward asteroid 2017 CS, closest on May 29. Another asteroid – 418094 (2007 WV4) – will be closest June 1. Charts here for Saturday night, for 8-inch or larger ‘scopes!

Today in science: Kennedy’s moon speech

On May 25, 1961, John F. Kennedy gave a stirring speech to a joint session of Congress, inspiring a nation to land humans on the moon with a decade.

What is a supermoon?

By at least 1 definition, the year 2017 has 4 supermoons. Three are new moons and not visible in our sky. The only full moon supermoon of 2017 will come in December.

The story behind the 2017 eclipse stamp

A 1st-of-its-kind stamp that changes when you touch it, commemorating the August 21, 2017 total solar eclipse. Fred Espenak – whose photos are on the new stamp – tells the story.

Humans and pufferfish share teeth genes

Our teeth evolved from the same genes that make the bizarre beaked teeth of the pufferfish, according to new research.

Did this human species coexist with our ancestors?

Fossil remains of Homo naledi found in a South African cave might be the first evidence of another species of hominin coexisting with the first humans in Africa.

Lake Baikal: Earth’s deepest, oldest lake

Controversy surrounds construction of hydropower stations on a river that feeds deep, ancient Lake Baikal.

Eta Aquarid over Mount Bromo

Cool short video of an early morning Eta Aquarid meteor over Mount Bromo in Indonesia, by Justin Ng. Take a few seconds and enjoy!

Watch 200th spacewalk Friday

Watch 2 astronauts perform landmark 200th ISS spacewalk on Friday, May 12. Live coverage begins at 6:30 a.m. EDT (10:30 UTC). Links to viewing here.

Imaging modern brains to study Stone Age thinking

We can’t observe brain activity of extinct human species. But we can observe modern brains doing things that our distant ancestors did for clues to how their brains worked.

Asteroid 2014 JO25: What we learned

This article from NASA’s Center for Near-Earth Object Studies provides fresh details on the closest approach by a large asteroid since 2004 … and shows you how science works.

Why did Tsavo lions eat people?

In 1898, a pair of lions ate 135 people at a railroad camp in Kenya. Scientists have analyzed microscopic wear on the lions’ teeth to find out why.

What happens in 1 minute

Just for fun, take 60 seconds to check out this new video from the guys at AsapSCIENCE.

What’s the birthstone for May?

Happy birthday May babies! Your birthstone, the emerald, is a type of beryl colored green by chromium. Perfect emeralds are among the rarest of gemstones.

Why do we celebrate May Day?

Happy May Day! A few words about this annual celebration, which has its roots in astronomy.

Why birds smash into windows

Up to 1 billion birds die each year in the U.S. due to collisions with windows. Why do birds slam into windows, and what can you do to prevent it?

New Project Skyglow video and giveaway

The guys at Project Skyglow have done some amazing videos, and they have a new book out. It’s not too late to enter their giveaway, honoring International Dark Sky Week.

Why cats can’t resist (even a phony) box

Twitter has been blowing up with posts on cats’ attraction to taped squares on the ground. An animal behavior expert explains what draws Fluffy to the #CatSquare.

This asteroid and comet look similar

Radar images of close-passing large asteroid 2014 JO25, which swept near last week, show it looks a lot like Comet 67P/Churyumov–Gerasimenko, which was explored by the Rosetta spacecraft.